--- gforth/hash.fs	1994/07/21 10:52:43	1.1
+++ gforth/hash.fs	1995/11/07 18:06:43	1.10
@@ -1,18 +1,36 @@
 \ Hashed dictionaries                                  15jul94py
 
-$80 Value Hashlen
+\ Copyright (C) 1995 Free Software Foundation, Inc.
+
+\ This file is part of Gforth.
+
+\ Gforth is free software; you can redistribute it and/or
+\ modify it under the terms of the GNU General Public License
+\ as published by the Free Software Foundation; either version 2
+\ of the License, or (at your option) any later version.
+
+\ This program is distributed in the hope that it will be useful,
+\ but WITHOUT ANY WARRANTY; without even the implied warranty of
+\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+\ GNU General Public License for more details.
+
+\ You should have received a copy of the GNU General Public License
+\ along with this program; if not, write to the Free Software
+\ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+11 value hashbits
+1 hashbits lshift Value Hashlen
 
 Variable insRule        insRule on
+Variable revealed
 
-\ Memory handling                                      15jul94py
+\ Memory handling                                      10oct94py
 
 Variable HashPointer
+Variable HashTable
+Variable HashIndex
 
-: hash-alloc ( addr -- addr )  dup @ 0= IF
-  Hashlen cells allocate throw over !
-  dup @ Hashlen cells erase THEN ;
-
-\ DelFix and NewFix is from bigFORTH                   15jul94py
+\ DelFix and NewFix are from bigFORTH                  15jul94py
 
 : DelFix ( addr root -- ) dup @ 2 pick ! ! ;
 : NewFix  ( root len # -- addr )
@@ -22,55 +40,110 @@ Variable HashPointer
 
 \ compute hash key                                     15jul94py
 
-: hash ( addr len -- key )  (hashkey)
-\  tuck bounds  ?DO  I c@ toupper +  LOOP
-  Hashlen 1- and ;
-
-: hash-find ( addr len wordlist -- nfa / false ) $C + @ >r
-  2dup hash cells r> + @ (hashfind) ;
-\  BEGIN  dup  WHILE
-\         2@ >r >r dup r@ cell+ c@ $1F and =
-\         IF  2dup r@ cell+ char+ capscomp 0=
-\	     IF  2drop r> rdrop  EXIT  THEN  THEN
-\	 rdrop r>
-\  REPEAT nip nip ;
+: hash ( addr len -- key )
+    hashbits (hashkey1) ;
+\   (hashkey)
+\   Hashlen 1- and ;
+
+
+: hash-find ( addr len wordlist -- nfa / false )
+    [ 3 cells ] Literal + @ >r
+    2dup hash r> xor cells HashTable @ + @ (hashfind) ;
 
 \ hash vocabularies                                    16jul94py
 
 : lastlink! ( addr link -- )
   BEGIN  dup @ dup  WHILE  nip  REPEAT  drop ! ;
 
-: (reveal ( addr voc -- )  $C + dup @ 0< IF  2drop EXIT  THEN
-  hash-alloc @ over cell+ count $1F and Hash cells + >r
-  HashPointer 8 $400 NewFix
-  tuck cell+ ! r> insRule @
-  IF  dup @ 2 pick ! !  ELSE  lastlink!  THEN ;
+: (reveal ( addr voc -- )  [ 3 cells ] Literal + dup @ 0< IF  2drop EXIT  THEN
+  @ over cell+ count $1F and Hash xor cells >r
+  HashPointer 2 Cells $400 NewFix
+  tuck cell+ ! r> HashTable @ + insRule @
+  IF  dup @ 2 pick ! !  ELSE  lastlink!  THEN  revealed on ;
 
 : hash-reveal ( -- )  (reveal) last?  IF
   current @ (reveal  THEN ;
 
-Create hashsearch  ' hash-find A,  ' hash-reveal A,  ' drop A,
-
-: (initvoc ( addr -- )  cell+ dup @ 0< IF  drop EXIT  THEN
-  insRule @ >r  insRule off  hash-alloc
-  3 cells - hashsearch over cell+ ! dup
-  BEGIN  @ dup  WHILE  2dup swap (reveal  REPEAT
-  2drop  r> insRule ! ;
-
-' (initvoc IS 'initvoc
+: addall  ( -- )
+    voclink
+    BEGIN  @ dup @  WHILE  dup 'initvoc  REPEAT  drop ;
+
+: clearhash  ( -- )
+    HashTable @ Hashlen cells bounds
+    DO  I @
+        BEGIN  dup  WHILE
+               dup @ swap HashPointer DelFix
+        REPEAT  I !
+    cell +LOOP  HashIndex off ;
+
+: re-hash  clearhash addall ;
+: (rehash) ( addr -- )
+  drop revealed @ IF  re-hash revealed off  THEN ;
+
+Create hashsearch  ' hash-find A, ' hash-reveal A, ' (rehash) A,
+
+\ hash allocate and vocabulary initialization          10oct94py
+
+: hash-alloc ( addr -- addr )  HashTable @ 0= IF
+  Hashlen cells allocate throw HashTable !
+  HashTable @ Hashlen cells erase THEN
+  HashIndex @ over !  1 HashIndex +!
+  HashIndex @ Hashlen >=
+  IF  clearhash
+      1 hashbits 1+ dup  to hashbits  lshift  to hashlen
+      HashTable @ free
+      addall
+  THEN ;
+
+: (initvoc) ( addr -- )
+    cell+ dup @ 0< IF  drop EXIT  THEN
+    insRule @ >r  insRule off  hash-alloc
+    3 cells - hashsearch over cell+ ! dup
+    BEGIN  @ dup  WHILE  2dup swap (reveal  REPEAT
+    2drop  r> insRule ! ;
 
-: addall  ( -- )  voclink
-  BEGIN  @ dup @  WHILE  dup (initvoc  REPEAT  drop ;
+' (initvoc) IS 'initvoc
 
 \ Hash-Find                                            01jan93py
 
 addall          \ Baum aufbauen
 \ Baumsuche ist installiert.
 
+: hash-cold  ( -- ) Defers 'cold
+  HashPointer off  HashTable off  HashIndex off
+  voclink
+  BEGIN  @ dup @  WHILE
+         dup cell - @ >r
+         dup 'initvoc
+         r> over cell - !
+  REPEAT  drop ;
+' hash-cold IS 'cold
+
 : .words  ( -- )
-  base @ >r hex context @ 3 cells +  HashLen 0
-  DO  cr  i 2 .r ." : " dup @ i cells +
+  base @ >r hex HashTable @  Hashlen 0
+  DO  cr  i 2 .r ." : " dup i cells +
       BEGIN  @ dup  WHILE
              dup cell+ @ .name  REPEAT  drop
   LOOP  drop r> base ! ;
 
+\ \ this stuff is for evaluating the hash function
+\ : square dup * ;
+
+\ : countwl  ( -- sum sumsq )
+\     \ gives the number of words in the current wordlist
+\     \ and the sum of squares for the sublist lengths
+\     0 0
+\     hashtable @ Hashlen cells bounds DO
+\        0 i BEGIN
+\            @ dup WHILE
+\            swap 1+ swap
+\        REPEAT
+\        drop
+\        swap over square +
+\        >r + r>
+\        1 cells
+\    +LOOP ;
+
+\ : chisq ( -- n )
+\     \ n should have about the same size as Hashlen
+\     countwl Hashlen 2 pick */ swap - ;